Information Gathering With WhatWeb Tool - Linux

This tool is bascially created for the website fingerprinting.It identifies the web technology and giving us the below details.This tool has more than 900 plugins to identify each and every information about the website in which you want to do fingerprinting. THis tools also supports the aggression level of the website. To control speed and reliability. 

Generally when you visit a website or a single page you can get much information about the site and much more. But sometimes it when you don't get any information then this WhatWeb comes in the pictures. It has an ability to interrogate the website in detail,in order to take out the further information of the website, server and much more.

Source : http://blog.tevora.com/info/whatweb-tool-for-pen-testers/